Aerobic workouts can be safely enjoyed by people with diabetes. These are fun exercises that can increase your muscle tone and aerobic fitness. A typical workout consists of greater-intensity aerobic work and lesser-intensity stretching and toning activities using hand-held or ankle weights and multiple repetitions (such as abdominal crunches). Classes vary in intensity based on individual ability and level of participation, as well as the nature of the class: high-impact, low-impact, step, hip-hop and others.

Beware of Hypoglycemia

The extended nature of aerobic workouts (45 to 90 minutes) usually causes blood sugars to drop in people with diabetes, so you may need to make changes in your diet and/or insulin to prevent hypoglycemia (see sidebar). The adjustments you make will depend on your exercise intensity and duration, the time of day you do aerobics, and your starting blood sugar levels. Longer classes and harder workouts will increase the impact on your blood sugars.

The Best Time to Exercise

In non-diabetic individuals, insulin production normally decreases during exercise, resulting in lower levels of circulating insulin. It is harder for people with diabetes to achieve a normal insulin response since insulin may be either overproduced by your body or introduced by injection. You will have an easier time maintaining your blood sugars if you exercise when circulating insulin levels are naturally lower, such as 3 to 4 hours after your last injection of short-acting insulin.

For morning exercises, you will generally need to eat fewer (if any) extra carbohydrates as your insulin resistance is highest at that time of day, prompting fewer precipitous drops in blood sugar levels during exercise.

Knowing When to Make Adjustments

A high-impact aerobics class will generally have more of a glucose-lowering effect than a low-impact one. If your blood sugar levels are elevated (150 to 300 mg/dl), you may not need to make any adjustments for an hour-long aerobics class. However, if your blood sugar levels are in a near-normal range (70 to 150 mg/dl), you will probably need to make some preventative adjustments, especially if you take insulin shots or certain oral medications. In those cases, eat some extra carbohydrates to maintain blood sugars. A good plan is to consume 10 to 15 gm. or the equivalent of one carbohydrate exchange. The best source is a carbohydrate that is rapidly absorbed by the body, such as juice, fruit or hard candy.

Insulin Users

Unless their dosage is reduced, insulin users may need to increase their carbohydrate consumption by as much as 15 to 30 gm. per hour of aerobic exercise following a short-acting insulin injection. Alternately, short-acting insulin doses can be lowered by 25 to 50 percent for exercise following a meal or during an insulin peak.

Insulin pump-users may reduce their basal rates by 50 to 100 percent during aerobics and/or lower their pre-exercise meal bolus by 25 to 50 percent to lower their insulin levels and eliminate the need for any extra food.

Exercise Requires Frequent Monitoring

Participation in aerobics usually requires more frequent blood sugar monitoring, especially when beginning, in order to determine your body's response to the exercise. You also need to be alert to the possibility of later-onset hypoglycemia, especially when you are a beginner or after unusually strenuous workouts.

Remember, having diabetes should not prevent you from exercising regularly, so make the necessary adjustments and have fun with it!